44 lines
1.2 KiB
Go
44 lines
1.2 KiB
Go
package gateway
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import (
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"bytes"
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"io/ioutil"
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"net"
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"os/exec"
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)
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func DiscoverGateway() (ip net.IP, err error) {
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routeCmd := exec.Command("route", "print", "0.0.0.0")
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stdOut, err := routeCmd.StdoutPipe()
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if err != nil {
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return
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}
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if err = routeCmd.Start(); err != nil {
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return
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}
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output, err := ioutil.ReadAll(stdOut)
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if err != nil {
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return
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}
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// Windows route output format is always like this:
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// ===========================================================================
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// Active Routes:
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// Network Destination Netmask Gateway Interface Metric
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// 0.0.0.0 0.0.0.0 192.168.1.1 192.168.1.100 20
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// ===========================================================================
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// I'm trying to pick the active route,
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// then jump 2 lines and pick the third IP
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// Not using regex because output is quite standard from Windows XP to 8 (NEEDS TESTING)
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outputLines := bytes.Split(output, []byte("\n"))
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for idx, line := range outputLines {
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if bytes.Contains(line, []byte("Active Routes:")) {
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ipFields := bytes.Fields(outputLines[idx+2])
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ip = net.ParseIP(string(ipFields[2]))
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break
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}
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}
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err = routeCmd.Wait()
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return
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}
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